1. Field of the Invention
This invention pertains to the computerizing of images for manipulation purposes and more specifically to the creation of data computed three-dimensional images for image projection and manipulation.
2. Description of the Prior Art
Images of objects can be created in numerous ways including photographs, negatives of photographs, x-ray radiographs, computed tomography images, magnetic resonance images, ultrasound images, and nuclear medicine scan images. All of these images produce a planar representation of the imaged object. When the imaged object is to be viewed relative to another imaged object, it is conventional to do so by having one of the objects, namely, the foreground object, put on a transparency so that the two images can be moved relative to one another. Alternatively, one object can be photographically projected on the other.
In either of the above cases, it is possible to shift one object up or down or sideways or a combination to orient one with other. It is not possible, however, with such planar object images to rotate or turn one object with respect to the other into or out of plane since both images are in two dimensions.
Although a second image view of the objects can be created in the same manner as the first, the second relationship of the object is still a planar relationship. It is still not possible to rotate one of the two images with respect to the other into or out of the plane.
An example of the use of two planar views of the type just described is in brachytherapy or the treatment of malignant tumors using implants of radioactive sources. When the tumor or tumors under treatment are in the vaginal area of the body, a Fletcher Suit Delclos gynecological applicator is commonly employed. Such a device is in the form of two components, a hollow cylinder that accepts a plurality of sequential or tandem radiation sources and a pair of ovoids, each of which accepts one source. In use, the applicator is inserted and positioned in the area of the tumor(s) to be treated. Positioning includes axial and lateral location as well as rotation. Once the device is properly positioned within the patient the radioactive sources are then inserted into the applicator components.
When such a radioactive implant is employed, it is important for the attending physician to know exactly where the sources are located to determine the distribution of the radiation dosage delivered by the implant. The physician is interested not only in the dose that is received by the tumor(s) but also that which is received by the surrounding normal body structures. This information allows the physician to design the implant so that the tumor(s) will receive an adequate therapeutic dose without exceeding the tolerance dose of the surrounding normal structure. In order to obtain the information required to describe the dose distribution characteristics of a particular implant, the exact location and orientation of the radioactive material or sources within the implant must be determined. Typically, two or more x-ray images of the implant are employed for the determination. The procedure involves mapping the location of each individual radioactive source in each of two x-ray film views and then entering this information into a computer. The computer then calculates and describes the dose distribution of the implant in question, all of which can be extremely time consuming. A particular problem occurs in this regard when the x-ray films are sub-optimal.
Therefore, it is a feature of the present invention to create a three-dimensional foreground image projection that can be manipulated in an universal manner, including rotation, with respect to a background image.
It is another feature of the present invention to utilize a three-dimensional foreground image of a device as one or more radiation dose sources and automatically determine the isodose mapping characteristics thereof with respect to a background image.